Single point vessel mooring system

ABSTRACT

A system to facilitate connection of a tanker or similar floating vessel to a single point mooring embodying loading and offloading facilities. The mooring includes a connecting hawser capable of restraining the vessel, and to which one or more fluid carrying conduits are attached. The hawser remote end is provided with a messenger line which is maintained in a substantially upright position above the water&#39;&#39;s surface. A catch mechanism depending from the vessel is thereby able, while moving through the water, to engage the messenger line preliminary to retrieving the hawser and fastening the vessel to the mooring.

United States Patent Wilbourn 1 Dec. 2, 1975 [5 1 SINGLE POINT VESSELMOORING 3.799.097 3/1974 Robertson ll4/206 R SYSTEM PrimaryExaminerGeorge E. A. Halvosa [75] Inventor. Li p. wllboum New OrleansAssistant Examiner-Stuart M. Goldstein Attorney, Agent, or Firm-T. H.Whaley; C. G. Ries; [73] Assignee: Texaco Inc., New York, NY. Robert B.Burns [22] Filed: May 29, 1974 [57] ABSTRACT [21] Appl. No.: 474,281

A system to facllltate connecnon of a tanker or s1m1lar floating vesselto a single point mooring embodying [52] U.S. Cl. 114/230 loading andffl di f ili i Thc mooring includes [5 l 1 Int- CLZ t a connectinghawser capable of restraining the essel [58] Field of Search 1 14/206 R,230, 221 R; and to which one or more fl id Carrying conduits are 9/8 9attached. The hawser remote end is provided with a I messenger linewhich is maintained in a substantially [56] References Cited uprightposition above the waters surface. A catch UNITED STATES PATENTSmechanism depending from the vessel is thereby able. 3,083,676 4/1963Anderson 114/230 While moving through the k to engage the 3,279 41910/1966 D Marco n 9 9 senger line preliminary to retrieving the hawserand 3.466.680 9/1969 Schirtzinger 1 114/230 fastening the vessel to themooring. 3.492.963 2/1970 Kaiser ll4/230 3.750.723 8/1973 Schirtzinger114/230 Clams, 14 Drawmg Figures Sheet 2 of4 I 3,922,992

U.S. Patent Dec. 2, 19 75 US. Patent Dec. 2, 1975' Shest 3 of43,922,992"

FIG. 4A

FIG. 3A

FIG. 8

SINGLE POINT VESSEL MOORING SYSTEM BACKGROUND OF THE INVENTION The useof single point moorings is becoming more widely prevalent and desirablein offshore waters to facilitate loading and offloading of vessels suchas tankers and the like. The advantage of such a mooring is that it isrelatively simple in construction, is capable of positioning a vesselaway from the ordinary traffic lanes and ship traffic characteristic ofa pier type operation. Further, it permits restrained movement of thevessel in response to wind and wave conditions without interrupting aloading or offloading operation.

Normally, a relatively large tanker has but limited maneuveringcapability which would permit it to pick up a hawser line from a mooringfor making the connection to the latter. The procedure usually followedis that a launch or similar small boat will physically carry the end ofthe hawser line to the tanker for making the necessary connection.Thereafter the one or more fluid carrying conduits depending from themooring can likewise be communicated with the unloading facility on atanker prior to effectuating transfer of liquids or fluids.

Often in the instance of a vessel mooring situation, however, wind andwave conditions are such as to render the use of a small boat tomaneuver the hawser line impractical. For example, when the weatherconditions result in wave heights of 6 to 8 feet, maneuverability of asmall boat is severely limited, and further the safety of personnel aswell as the boat are jeopardized during the operation.

Toward minimizing the use of launches and smaller vessels to achieve amooring connection, means is provided as disclosed herein whereby thesingle point mooring includes one or more connecting hawsers. The lattercan either float or be submerged beneath the waters surface. In eitherevent the remote end of the heavy hawser is provided with a messengerline having an upstanding portion, which is maintained a desireddistance beyond the waters surface.

The vessel to be moored is provided with a retractable catch mechanism,preferably attached to the forward end thereof. Said mechanism isoperably positioned to engage the messenger line as the vessel, whileslowly moving, is steered into contact with the latter. Thereafter, themessenger line can be readily drawn aboard the vessel, thus permittingthe hawser to likewise be retrieved, and the physical connection betweenmooring and vessel completed.

DESCRIPTION OF THE DRAWINGS In the drawings,

FIG. 1 is a vertical elevation illustrating a mooring of the typecontemplated prior to being connected to a floating vessel.

FIG. 1A is a top view of FIG. 1.

FIG. 2 is an enlarged segmentary view of the mooring shown in FIG. 1.

FIG. 2A is a top view of FIG. 2.

FIG. 3 is a segmentary view of the forward end of a vessel showing thecatcher mechanism in retracted position.

FIG. 3A is a top view of FIG. 3.

FIG. 4 is similar to FIG. 3 illustrating the catch mechanism in theoutward position.

FIG. 4A is a top view of FIG. 4.

FIG. 5 is similar to FIG. 1 illustrating the vessel connected to themooring.

FIG. 5A is a top view of FIG. 5.

FIG. 6 is a segmentary view on an enlarged scale of the connectionbetween the hawser and the messenger line.

FIG. 7 is an enlarged'view of the connector shown in FIG. 2.

FIG. 8 is a top view of FIG. 7.

FIG. 9 is a cross-sectional view taken along 9-9 in FIG. 2A.

Referring to the drawings, FIG. 1 represents an offshore mooring 10 ofthe type contemplated, which is normally referred to as a single pointmooring. The mooring is characterized in general by an upright floatingbody 11, usually of cylindrical construction, and including flexibleconduit means 12 to communicate with an underwater pipeline 13. Thelatter extends from a shore or submerged installation, to conduct fluidsto and from the vessel.

Pipeline 13 is either buried, or can rest on the ocean floor, andterminates adjacent the mooring l0. Said pipeline 13 is connected to thelatter by means of one, and usually by a plurality of intermediate,flexible conduits which pass upwardly through the water and are engagedby appropriate valve means to external liquid carrying conduits 14.

Mooring 10 is held in place over a limited area of ocean floor by anchorlines 16 and 17, preferably a plurality thereof being disposed about themooring, and having their ends fixed or anchored into the ocean floor.Thus, the outwardly radiating pattern of the respective anchor linespermits the mooring to readily vacillate in response to the watermovement. However. lateral movement is restrained to a limited distanceagainst displacement in response to water and wind action, as well as tolateral displacement in response to a tanker 18 being connected thereto.

Mooring 10 is provided with a rotatable head 19 into which therespective conduits 14 and one or more hawsers 26 are communicated.Thus, the respective conduits 14 will be freely rotated about themooring as tanker 18 is rotated by wind, wave and tide action, and yetnot interfere with the fluid flow therebetween.

The primary advantage of the present arrangement resides in that, asherein mentioned, tanker 18 can be loaded or offloaded as the case maybe while remaining a distance out to sea rather than drawn up to astationary unloading pier or the like.

Vessel 18 will be referred to for the present descriptive purpose as atanker adapted to carry crude or refined petroleum products to and frompoints of use. Tanker 18 is, in the normal manner, provided with aforward end or bow which can also embody the loading and unloadingfacility in the form of valved connections and manifolds to whichexternal mooring conduits 14 are removably attachable.

To effectuate the initial connection between floating mooring l0 and themoving vessel 18, the latter is provided with a catch mechanism 21embodying one or more arms 22 and 23. Said arms, when not in use arenormally collapsed backward against the sides of vessel 18 as shown inFIGS. 1 and 1A. When in the operating position, the arms 22 and 23 areadvanced forward to an open position as shown in FIGS. 4 and 4A todefine a converging, line catching area therebetween. Thus, as

one of the open arms 22 or 23 engages an upstanding messenger line 24,the latter can be drawn aboard the vessel and rapidly retrieved by winch33 to bring the end of the mooring hawser 26 into locked engagement witha connecting means on the vessel.

Mooring as herein noted comprises a cylindrical body 11 which ismaintained uprightly in a floating position at the water's surface byinternal buoyancy means. Normally body 11 is provided with acircumferential shock absorbing or bumping arrangement 27 to withstandimpacts with moving vessels and the like as the latter comes into severecontact with the mooring.

Mooring 10 is provided on its upper side with rotatable or pivotallyconnected head 19 which can assume a number of embodiments known in theart. The purpose of said head 19 is to permit independent rotatablemovement between the head and body 11 as vessel 18 and the connectingconduits 14 are moved in a floating position about the mooring.

The physical structure of rotatable head connection 19 is such that inspite of the amount of relative movement between vessel 18 and mooring10, a loading or unloading operation can be maintained continuously.External conduits 14 are fabricated to normally float at the waterssurface or they can be so maintained by the use of spaced apart buoyancymembers 29. While there are presently shown two such conduits 14 whichextend from head 19 and connected to the vessel, it is understood thatany number of such conduits can be utilized in the practice of theinvention.

Preferably, mooring hawser 26 is connected to the respective conduits 14by means of an elongated bracket 31, as shown in FIGS. 7 and 8. Saidbracket engages the respective conduits 14 and mooring hawser 26,whereby to maintain a desired rigid spacing therebetween near the hawserremote end. Thus, as hawser 26 is drawn from the water and onto a vesselduring the mooring pick-up operation, conduits 14 can similarly bebrought aboard and subsequently fitted to appropriate connections on thevessel.

Each conduit 14 is provided with a flange 32 or similar fitting adaptedto removably but rapidly engage the mating portion of such member onvessel 18. With respect to the mooring hawser 26, the latter is fastenedat one end to the mooring head 19 and can be supported on the waterssurface. The remote end of hawser 26 is provided with a tag line 36having a loop 34 or similar fitting which accommodates an upstandingmessenger line arrangement 24.

Referring to FIG. 2, messenger line 24 includes in effect a connectorsuch as a shackle 37 or the like adapted to removably engage a similarfastening loop 34 on the end oftag line 36. A messenger line cable 24depends from shackle 37 and is normally maintained in a substantiallyvertical disposition by any of several means including the presentlyshown inflatable balloon 41 which rises a predetermined distance abovethe waters surface as to be readily retrieved.

Preferably, the messenger line 24 includes a flexible cable or rope,although said member can with some degree of advantage assume the formof a rigid structural member such as tubing and the like havingappropriate flexing joints. However, in that said member 24 must resistthe sudden impact of a vessels catch mechanism engaged therewith, saidmember is preferably resiliently constructed, or embodies a degree ofresilience therein which would permit it to withstand the shock of apick-up operation.

Messenger line 24 is maintained in its substantially upright dispositionby a self-supporting expandable member such as balloon 41 or the likehaving means to introduce an expanding medium thereto. It is appreciatedthat when so supported, the messenger line will be free to be deflectedin response to the wind force acting against the balloon 41. The balloonis normally maintained in an inflated condition to facilitate a pick-upoperation and to identify the position of the buoy, particularly atnight. Thus, balloon 41 may be provided with an outer radar beamreflective surface, or alternately with a radar reflecting memberattached thereto.

Under such conditions, the vessel can accurately approach its mooringposition merely by permitting the reflected balloon to function as aradar reflector.

Toward assisting in the pick-up operation, messenger line 24 can beprovided with an outwardly radiating collar preferably in the form of aplurality of discrete, laterally spaced fingers 42. The latter are socurved and constructed that as the outstretched arms 22 and 23 dependingfrom the vessel engage the messenger line 24, forward movement of thevessel will eventually permit the messenger line to be guided along thearms as to be picked up and attached to the winch 33. As a safetymeasure, the downwardly projecting fingers 42 are so adapted to engagean arm 23, such that the arms will not tend to pass over the balloonthereby freeing it from the intermediate area between the respectivearms.

While not presently shown, balloon 41 or messenger line 24 can furtherbe provided with a lighting means. Provision of the latter is usuallygoverned by governmental navigational requirements toward the lightingof a floating or fixed object in any navigable waters.

The presently disclosed arms 22 and 23 are operably connected to theforward end of the vessel 18, but may alternately be attached to therear or stern end should mooring in such a position be deemed desirable.As shown, the respective arms 22 and 23 are disposed at the bow of thevessel 18, being pivotally connected to the latter such that they may bepositioned as shown in FIGS. 3, 3A, 4 and 4A, in either the extended orthe retracted position.

Each arm comprises in effect a hinged joint 43 which operably connectsthe arm to the bow of the vessel for movement in a substantiallyhorizontal plane. Each arm is of a sufficient length such that when inthe extended position it covers a substantial intermediate area. Theoperable range of arms 22 and 23 can be extended if weather deems, bystructuring the arms to be telescopically adjustable. This scope in thearms coverage facilitates the pick-up operation even though the balloon41 is subjected to excessive wind and wave action, and might be forcedinto a lower altitude due to displacing action of the wind.

While presently shown as being fixed to the bow of vessel 18, therespective arms can also be carried on a carriage or similar apparatusadapted to move in a vertical direction on a track or similar guidemeans 44 fixed to the bow of the boat. Thus, the entire arm mechanism asshown in FIG. 1, can be preset to a desirable elevation above waterlevel depending on the condition of the vessel whether loaded orunloaded, and on the weather conditions, both of which would affect thedisposition of messenger line 24. Functionally, during a mooringoperation the vessel advances slowly in a direction toward theupstanding messenger line 24.

At such time as the outspread arms 22 and 23 come in contact with themessenger line, the forward movement of the vessel will tend to guidethe line along one arm until it is drawn into contact with the vesselitself.

Thereafter the messenger line is turned onto winch 33 such that theballoon and messenger line can be rapidly drawn aboard the vesselthereby bringing the hawser 26 onto the deck. As the forward end of thehawser is made fast to the deck, the vessel is in effect tethered andready to be connected to the fluid carrying conduits 14.

Referring to FIG. 7, toward facilitating the connecting operationbetween the mooring and a vessels tanks, the respective conduits 14 areengaged with hawser 26 by a rigid bracket 31 shown therebetween. As thehawser 26 is drawn onto the boat, it also can be winched in such manneras to lift the remote ends of the respective conduits 14. Since thesemembers are relatively heavy, the lifting of the conduits can be aidedthrough use of a suitable hoist or equipment positioned at the bow ofthe boat to aid in such an operation.

With the ends of conduits 14 positioned on deck, bracket 31 can bequickly and easily removed thus permitting the respective conduits to becommunicated with the appropriate shipboard manifold or connection priorto passing fluid therethrough.

In accordance with the particular structure of the vessel, the loadingand unloading manifold stations may be at the forward end of the vesselimmediately adjacent to the bow. Alternately, however, these connectionscan be located toward the boat center. In any event the respectiveconduits 14 can be positioned with respect to the vessel so as tofacilitate the loading and yet permit the vessel to swing freely aboutits mooring 10.

After a cargo transfer has been completed, the vessel can be readilydetached from the mooring and get underway. This is achieved by areversal of the steps followed in the mooring operation. Thus, thehawser 26 is detached from the vessel and the messenger line 24 isconnected to the tag line. With the balloon 41 inflated, the hawser isreleased so that the vessel can back from the mooring and get underway.

Other modifications and variations of the invention as hereinbefore setforth may be made without departing from the spirit and scope thereof,and therefore, only such limitations should be imposed as are indicatedin the appended claims.

I claim:

1. System for engaging a vessel floating at the waters surface to amooring positioned in a body of water, said mooring including aconnecting hawser having one end thereof depending from the mooring, andbeing of sufficient length to position the hawser other end a distancefrom the mooring,

a messenger line depending from said hawser other end and beingsupportably elevated to a substantially upright position above thewaters surface,

a catch mechanism depending from said vessel to engage and retain saidmessenger line as the vessel moves into contact therewith,

said catch mechanism including at least two outstanding arms operablycarried on the vessel emanating from a common point on said vessel andpositioned outwardly of the point to define an area between said armswhich converges toward the vessel,

whereby said hawser other end can be drawn onto and connected to saidvessel for restraining further movement of the latter.

2. In an apparatus as defined in claim 1, wherein said hawser includesmeans for maintaining at least a portion of said hawser floatably at thewaters surface.

3. In an apparatus as defined in claim 1, wherein said catch mechanismincludes a messenger line winch mechanism depending from the vessel andadapted to engage said messenger line end after the latter has beenreceived between said arms, for drawing said messenger line in, andsubsequently drawing the hawser onto said vessel.

4. In an apparatus as defined in claim 1, wherein said line catchmechanism includes at least two arms operably connected to the vesseland adapted to be pivotally adjusted outwardly from a position adjacentthe vessels sides, to form said area therebetween whereby to engage saidupstanding messenger line as the vessel is guided through the watertoward the latter.

5. In an apparatus as defined in claim 1, wherein said at least two armsare operably engaged to said vessel bow at a point adjacent to saidwinch mechanism.

6. In an apparatus as defined in claim 1, wherein said catch mechanismis operably carried on said vessels bow and including means at said bowfor adjusting said catch mechanism in a vertical direction.

7. In an apparatus as defined in claim 1, wherein said messenger lineincludes a collar carried adjacent the line upper end and being adaptedto engage said catch mechanism.

8. In an apparatus as defined in claim 7, wherein said collar includes aplurality of fingers depending radially from said messenger line tocontact said catch mechamsm.

9. In an apparatus as defined in claim 4, wherein said catch mechanismat least two arms are telescopically constructed.

10. In an apparatus as defined in claim 1, wherein said respective atleast two arms when outwardly positioned are disposed in a substantiallyhorizontal plane.

1. System for engaging a vessel floating at the water''s surface to amooring positioned in a body of water, said mooring including aconnecting hawser having one end thereof depending from the mooring, andbeing of sufficient length to position the hawser other end a distancefrom the mooring, a messenger line depending from said hawser other endand being supportably elevated to a substantially upright position abovethe water''s surface, a catch mechanism depending from said vessel toengage and retain said messenger line as the vessel moves into contacttherewith, said catch mechanism including at least two outstanding armsoperably carried on the vessel emanating from a common point on saidvessel and positioned outwardly of the point to define an area betweensaid arms which converges toward the vessel, whereby said hawser otherend can be drawn onto and connected to said vessel for restrainingfurther movement of the latter.
 2. In an apparatus as defined in claim1, wherein said hawser includes means for maintaining at least a portionof said hawser floatably at the water''s surface.
 3. In an apparatus asdefined in claim 1, wherein said catch mechanism includes a messengerline winch mechanism depending from the vessel and adapted to engagesaid messenger line end after the latter has been received between saidarms, for drawing said messenger line in, and subsequently drawing thehawser onto said vessel.
 4. In an apparatus as defined in claim 1,wherein said line catch mechanism includes at least two arms operablyconnected to the vessel and adapted to be pivotally adjusted outwardlyfrom a position adjacent the vessel''s sides, to form said areatherebetween whereby to engage said upstanding messenger line as thevessel is guided through the water toward the latter.
 5. In an apparatusas defined in claim 1, wherein said at least two arms are operablyengaged to said vessel bow at a point adjacent to said winch mechanism.6. In an apparatus as defined in claim 1, wherein said catch mechanismis operably carried on said vessel''s bow and including means at saidbow for adjusting said catch mechanism in a vertical direction.
 7. In anapparatus as defined in claim 1, wherein said messenger line includes acollar carried adjacent the line upper end and being adapted to engagesaid catch mechanism.
 8. In an apparatus as defined in claim 7, whereinsaid collar includes a plurality of fingers depending radially from saidmessenger line to contact said catch mechanism.
 9. In an apparatus asdefined in claim 4, wherein said catch mechanism at least two arms aretelescopically constructed.
 10. In an apparatus as defined in claim 1,wherein said respective at least two arms when outwardly positioned aredisposed in a substantially horizontal plane.